http://www.ck12.org Chapter 12. Rigid Transformations
Glide Reflections
Now that we have learned all our rigid transformations, or isometries, we can perform more than one on the same
figure. In your homework last night you actually performed a composition of two reflections. And, in the Review
Queue above, you performed a composition of a reflection and a translation.
Composition (of transformations):To perform more than one rigid transformation on a figure.
Glide Reflection:A composition of a reflection and a translation. The translation is in a direction parallel to the line
of reflection.
So, in the Review Queue above, you performed a glide reflection onABCD. Hopefully, in #4, you noticed thatthe
order in which you reflect or translate does not matter. It is important to note that the translation for any glide
reflection will always be in one direction. So, if you reflect over a vertical line, the translation can be up or down,
and if you reflect over a horizontal line, the translation will be to the left or right.
Example 1:Reflect 4 ABCover they−axis and then translate the image 8 units down.
Solution:The green image below is the final answer.